Aircraft landing gear



,Fell 8 1949- c. R, LlvERMoN 2,461,288

AIRCRAFT LANDING GEAR Filed April l0, 1945 Patented Feb. 8, 1949u.ni-renv srl-tres Arent rifica This invention `relates to aircraftlandingV gearand more particularlyto gear wherein the landing wheels aregiven al forward spin preparatory to landing for the purpose of reducingtire wear and minimizing landing shock.

An object of the invention is to provide greatly improved landing gearof this type utilizing dynamic energy .of fluid to impart rotation tothe wheels.

Another object is to provide uid driven turbine means for rotating thewheels.

AnotherV object is to provide landing gear having a turbine rotorelementassociated with a landing wheel and power means. associated withtherelatively Xed structure of the aircraft for directing impellingfluid against the rotor.

Still another object is to provide, in such landing gear, wheel startingmeans employing an explosive substance to furnish the necessary power.

Other objects and advantages of the invention will be in part apparentand in part pointed outin the following description when considered inconnection with the accompanying drawing, wherein:

Fig. lis a sectional View of a landing wheel and strut embodying theinvention, parts being shown in elevation;

Fig. 2 is a yright side partial view of the wheelr of Fig. 1, partly insection, and with other parts broken away;

Fig. 3is a plan view. of a modified form of Wheel and strut embodyingthe invention; and

Fig. 4 is asohematic viewillustrating a iurtherA modification.

Referring'particularly to Figs. l and 2 of the drawing, depicting thepresently preierredform of 'the invention, there is shown one element ofaaconventional .retractable aircraft landing gear including the usualstrut 5, pivoted at (i to the aircraft for retraction by conventionalmeans (not shown). It will be understood vthat the strut is shown nlanding position, and thatit may be pivoted in a counterclockwisedirection for retraction. A'wheel 'l is mounted on suitable bearings-onaspindle 8 carried by the strut.

The wheel starter of the invention comprises, iii-brief, a bladedturbine rotor mounted on the landing wheel and means carried -by arelatively fixedv part oi the aircraft for directing Aa streamofi-,fluid at high velocity against the blades of the turbine'rotor toimpelt the rotor and thus to drive the wheel.

The turbine rotor, designated by the general reference-l numeral. '9;may be constructed; as g slioWri-fY by;. .welding to the disc. portion;Yi il @offthef 6 Claims. (Cl. 24d-103) S51-@through the rotor,givinggnp-somefofy their 2 Wheel .a number of blades or cups :l l and`suit-2. ably securing tc theaxially inner edgesof the blades,.as byWelding, a ring i2." There isthus provided abladed turbiney rotorthroughwhich an impelling fluid .may flow radially outward: About theperiphery of the roton'thereis .secure-:1; anv annular safety screen it,throughfwhich im-` pelling fluid, such as gas, leaving the-rotor blades.must pass in order to reach. the atmosphere.. The Vsafetyscreen may haveonezofzits edges welded to the outer edge ofring andthe other... of itsedges Welded to the disc portion lil of 'the wheel. more particularlypointed out hereinafter. It will. be apparent` that the turbine rotor,the safety-` screen, and the wheel forni ane` integral,.structnre;A1 andthat torque applied to the rotor willbe transmitted directly to theWheel. Y

The preferred mean-s for. directing a stream-voriy jet of impellingiiuid against the blades-1.0i 'thef rotor is shown in Figs..1-and2ascomprisingfa plural-ity of open-ended cartridges icarried byl an annularsupporting frame igf. fastened bye screws I3 to ailange il' formingapart,of-athe. strut-5. Asbest seen in FigeZ; each-cartridge isremovably supp-ortedaonffthe-frame, tl'iefyfeai,YYY ofthecartridgebeingsupportedbyfa bracket 1B@ secured to the frameqi; a A`pinIEB Ibeinggprovided; at the rear of the cartridgecase for engagement ina hole in the.bracket.- The -forward-endsfof the cartridgeis.supportedfbyl meansoiv anfine. tegral arm 2e fastened to theframenya-screw 2l. Spent cartridgesmay be readilyreplaced. by

removing screws 2L whereupon. the 'cartridges'- may -be bodily removed.Fresh cartridges inay;

vtric Isquib ZSfiorigniting the-charge; The squib is. of the singlelwire type,being-groun'dedito the cartridgev case yand-having aterminalsjZlt z which?.

makes electrical contact Witha contact-'ring 25s:

carried by an' insulating ring `2l:`-.,-u1: on. the. frame I5.Y Thesquibs are .firediirom battery#2l'by;-.y switch 28, thef circuitbeingcompleted-through*- ground on one-sideand'onftheothergside.through-V' lead wire 29=attached-to cont-actfringe25.:-4

It will ,be .observed` that the fior-wardI -fendsfgfg of Vthe cartridgecases are-opento provide nozzlesfor the issuance bf ,f gaseous f powdercombustion f products and-to direct the stream of gaseousprod.-

ucts.- againstfthe blades; l l of "they-.turbine rotor,

fordriving thalatter: rlhe powdenfgases pass-i The purpose ofthe safetyscreen rwill beiy and thence pass through the safety screen I 3, whichserves to cool the gases and arrest sparks, thereby minimizing thelikelihood of damage to the aircraft.

In order to obviate accidental discharge of the cartridges when thewheels are retracted, a safety switch 3| is included in the insulatedpart of the electric circuit. One element of the switch is carried bythe movable part of the strut and the other element is carried by thefixed part. It will be apparent from inspection of the drawing that theswitch will be open when the landing wheel is in retracted position sothat accidental operation of switch 28 will not serve to nre thecartridges.

In operation, the wheels of the aircraft are lowered preparatory tolanding. Just prior to making contact with the ground, switch 28 isclosed and the cartridges are red. Combustion gases at high velocityimpinge upon the blades of the rotor and cause the latter to rotate,which motion is imparted tothe wheels. It will be understood that thequantity of powder employed will be chosen with regard to the moment ofinertia of the wheel, to the landing speed of the aircraft, and to otherfactors involving considerations of mere design, as well known to thoseskilled in the art to which this invention pertains.

The modiiication of the invention shown in Fig. 3 differs from thatshown in Figs. 1 and 2 primarily in that the flow of impelling gasesthrough the turbine is in a direction axially of the wheel rather thanradially. This requires certain structural changes which will be readilyunderstood in the light of the previous description. In Fig. 3, partsanalogous to those previously described will be designated by the samereference numerals, to which primes have been appended.

The turbine rotor 9 has passageways between the blades II' which areopen at the right and left hand sides, as seen in Fig. 3. The blades IIserve as wheel spokes in addition to performing their normal function inthe rotor. screen I3' overlies the low pressure openings of the turbinerotor and cools the issuing gases to prevent damage to the aircraft.

The cartridges I4 have side openings 38 directed towards the rotor. Thecartridges are removably supported on the frame I5' in a front bracketI8 by a lug I 9' received in a hole in the front bracket, and by a reararm 2li' fastened to the frame by means of a screw 2l.V The electricalcircuit for firing the squibs 23' is similar to that described inconnection with Figs. 1 and 2 and includes contact ring 25 and lead wire28. The contact ring is mounted on the insulating ring 26.

The operation of the wheel starter shown in Fig. 3 is identical with theoperation of that shown in Fig. 1 and 2, and the cartridges are just asreadily replaced.

The principles of this invention may be adapted to utilize a liquidinstead of a gas as the impelling iiuid. Fig. 4 diagrammaticallyillustrates such an adaptation. In this figure, reference numeral S"represents a turbine rotor attached to an aircraft landing wheel and 30"represents a nozzle carried by a relatively stationary or fixed part ofan aircraft. A conduit 32" leads back from the nozzle to a tank I4containing liquid such as water. A source of compressed air 21 isconnected through conduit 29" including valve 28" to the liquidcontainer I4. y

When it is desired to start the wheel, valve 28" is opened andcompressed air from tank 2 forces liquid from the tank III throughconduit 32 to nozzle 30". The nozzle directs a high velocity stream ofliquid against the blades of the turbine rotor 9 causing the latter toturn the landing wheel to which it is attached.

From the foregoing description, it is evident that the present inventionprovides a simple yet efiicient wheel starter for aircraft landing gearutilizing fluid driven turbine means for rotating the wheel.

Obviously, the invention is not restricted to the particular embodimentsthereof herein shown and described. Various changes may be made withoutdeparting from the spirit of the invention as set forth in lthe appendedclaims.

I claim:

1. In an aircraft landing gear of the character described, incombination, a landing Wheel strut; a landing wheel rotatably mounted onsaid strut;

turbine rotor carried by said wheel; blades having inlet edges on saidrotor a cartridge supporting frame ixed to said strut adjacent saidwheel; a cartridge having an open-ended case defining a nozzle orificesupported on said frame, the oriiice of said case being positionedclosely adjacent the blades of said rotor and so constructed as toconi'orin to a sector' of the path of the inlet edges of said blades andto direct a stream of impelling gas against the blades of said turbinerotor, said cartridge containing an explosive charge; electric ringmeans for igniting said charge; a source or electric current; andcircuit means inciuding an operating switch connecting said source ofcurrent to said firing means.

2. The combination defined in claim 1 wherein the turbine rotor isconstructed and arranged for radial now of impelling fluid between theblades.

3. The combination defined in claim 1 Wherein the turbine rotor isconstructed and arranged for axial new of impelling fluid between theblades.

4. In an aircraft landing gear of the character described, incombination, a landing wheel strut; a landing wheel rotatably mounted onsaid strut; a bladed turbine rotor carried by said wheel; a safetyScreen carried by said Wheel and interposed between the low pressureside of said turbine rotor and the atmosphere, whereby exhaust gasesfrom said rotor will pass through the screen tothe atmosphere: acartridge supporting frame fixed to said strut adjacent said wheel; acartridge having an open-ended oase defining a nozzle orifice supportedon said frame, the oriice of said case being positioned to direct astream of impelling gas against the blades of said turbine rotor, saidcartridge containing an explosive charge, electric firing means forigniting said charge, a source of electric current; and circuit meansincluding an operating switch connecting said source of current to saidfiring means.

5. In an aircraft landing gear of the character described, incombination, a landing wheel strut; a landing wheel rotatably mounted onsaid strut; a bladed turbine rotor carried by said wheel; a safetyscreen carried by said wheel and interposed between the low pressureside of said turbine rotor and the atmosphere, whereby exhaust gasesfrom said rotor will pass through the screen to tioned to directa streamof impelling gas against.

the blades of said turbine rotor, said cartridge containing an explosivecharge, electric firing means for igniting said charge, a source ofelectric current; and circuit means including arreperatng switchconnecting said source of current to said firing means.

6. 1n an aircraft landing gear of the character described, incombination, a landing Wheel strut; a landing Wheel rotatably mounted onsaid strut; a blacled turbine rotor carried by said Wheel; a cartridgesupporting frame xed to said strut adjacent said wheel; a plurality of`cartridges spaced uniformly around said rotor, each said REFERENCESCITED The following references are of record in the iile of this patent:

UNTED STATES PATENTS Number Number Name Date Freund Mar. 16, 1875 LibbeySept. 4, 19Go Flucks Feb. 21, 1965 Murray May 21, 1918 Woolson Oct. 25,1932 Lansing Apr. 18, 1939 Pevney Sept. 15, 1942 Finnegan Apr. 13, 1943Vickers et al Dec. 12, 1944 Juul Feb. 2'?, 1945 Kendrick Mar. 27, 1945New Nov. 26, 1946 FOREIGN PATENTSr Country Date ermany Dec. 18, 1940

